Problematic peer relations, particularly when chronic, can have a tremendous impact on children's functioning and mental health. Decades of research indicate that peer rejection, isolation, and victimization negatively impact adjustment and place children at increased risk for a myriad of later negative outcomes. Prevention and treatment research supports the use of social skills group therapy for improving children's peer relations, social behavior, and emotional adjustment. However, focusing exclusively on the child is not as effective as multi-component intervention efforts that extend beyond the group setting. This Competing Renewal project will continue the research and development of a parent-focused intervention, Parent Guide to SSGRIN, which parallels an established child-focused intervention [Social Skills Group Intervention (S.S. GRIN);for children ages 5-12years], in order to teach and reinforce the same social skills and concepts within the home environment. Phase II objectives of creating the complete Parent Guide intervention product and conducting pilot efficacy research were successfully accomplished. However, the limited scope of the Phase II research project leaves critical questions unanswered regarding the treatment's effectiveness, particularly its relative impact above and beyond the SSGRIN intervention alone. As 3-C ISD has moved the Parent Guide product into Phase III commercialization, it has become increasingly evident that further R&D is critical to commercializing this product. Therefore, a primary goal of this Competing Renewal is to conduct a rigorous, large-scale, longitudinal research project that is adequately powered to address questions of relative impact, longer-term treatment benefits, and differential treatment effects across settings and populations. Another lesson learned during Phase II and subsequent commercialization efforts is that the Parent Guide's current design is impractical for the school setting. Though schools often struggle with how to increase parent involvement in school-based programs, school officials report that it is infeasible for them to conduct the full series of in-person parent training groups as the Parent Guide's current curriculum demands. As a result, the commercial potential for the product is greatly restricted. Therefore, a second goal of this Competing Renewal is to incorporate Phase II findings, commercialization feedback, and stakeholder input into the creation of a Home-study version of the Parent Guide, which would utilize 3-C's innovative web- and video- based technology to bridge training into the home environment. Once developed, the Home-study version of the Parent Guide will be included as a separate treatment condition within the effectiveness trial and will also be evaluated for feasibility specifically within the school setting. The proposed Competing Renewal project will support further product development so that the Parent Guide can be successfully extended into the school setting, a primary mental health service sector for children, and will also ensure extensive, large-scale testing of this product to address key research questions that are imperative for achieving both scientific and commercial goals